FR2868509B1 - LIGHT EMITTING DIODE HEADLIGHT FOR VEHICLE - Google Patents

Abstract

A vehicle headlight comprises: a first light source module (10b; 10c) having semiconductor light emitting elements; a first optical element for applying light generated by the first light source module (10b; 10c) to an area of the light distribution model of the vehicle headlight; a second light source module (10a) which has semiconductor light emitting elements and generates light having a higher brightness than that of the light of the first light source module (10b; 10c) ; and a second optical element for applying the light generated by the second light source pattern to an area narrower than the area on which light is applied by the first optical element.

Description

The present invention relates to a vehicle headlight and an automobile headlight. More particularly, the present invention relates to a headlight used for a vehicle and to a headlamp used for an autobob i1e.

A lighting device for a vehicle using a semiconductor light emitting element such as an LED (light-emitting diode) has been known for the last few years (see, for example, JP-A-2002-231013 ( pages 2 to 6, Figures 1 to 13)). In addition, the use of the semiconductor light emitting element such as the LED for a vehicle headlight, for example, from the viewpoint of its design has been investigated. A vehicle headlight shall form a prescribed light distribution pattern from a safety point of view. A light distribution pattern includes an area called a hot zone that needs to be illuminated with light brighter than other areas in the light distribution pattern.

In order to brightly illuminate the hot zone with light, a high brightness light source is preferably used to condense the light having a high light intensity on the hot zone and to illuminate the hot zone with the light. In order to generate the high brightness light, the light source can be used to generate light having a large light flux. However, when a semiconductor light emitting element such as an LED generates light having a large light flux, the light emission efficiency can sometimes be deteriorated. As a result, the power consumed by the vehicle headlight is undesirably increased.

Thus, the present invention aims to provide a vehicle headlight and a car headlight capable of solving the problem described above.

In order to solve this problem, according to a first aspect of the present invention, a vehicle headlight comprises: a first light source module having at least one semiconductor light emitting element; a first optical element for applying light generated by the first light source module to an area of a light distribution pattern of the vehicle headlight; a second light source module having at least one semiconductor light emitting element and generating light having a higher brightness than that of the light of the first light source module; and a second optical element for applying the light generated by the second light source pattern to an area narrower than the area on which light is applied by the first optical element.

The vehicle headlamp described above may further include: a first source of electric current for supplying an electric current to the first light source module; and a second electric power source for supplying to the second light source module an electric current such as the current density of the electric current supplied to the semiconductor light emitting element provided in the second source module. of light is higher than the current density of the electric current supplied to the semiconductor light emitting element provided in the first light source module. The semiconductor light emitting element of the second light source module may have a smaller light emitting area than that of the semiconductor light emitting element of the first source module light source and the second source of electric current can deliver to the second light source module the electrical current substantially equal to the electric current delivered to the first light source module by the first source of electric current. The semiconductor light emitting element of the second light source module may have a light emitting surface substantially equal to that of the semiconductor light emitting element of the first source module light source and the second source of electric current can supply to the second light source module an electric current greater than the electric current supplied to the first light source module by the first electric power source.

The first light source module may include a plurality of parallel-connected semiconductor light-emitting elements having substantially equal light-emitting surfaces, the second light-source module may include a plurality of semiconductor light emitting elements connected in series and having the light emitting surfaces substantially equal to those of the multiplicity of semiconductor light emitting elements included in the first source module of light and the second source of electric current can deliver to the second light source module an electric current substantially equal to the electric current delivered to the first light source module by the first source of electric current.

According to a second aspect of the present invention, an automobile headlight for applying a passing beam used for a vehicle comprises: a first light source module having at least one semiconductor light emitting element; a first optical element for applying light generated by the first light source module to an area of the vehicle headlight light distribution pattern; a second light source module having at least one semiconductor light emitting element and generating light having the brightness greater than that of the light of the first light source module; and a second optical element for applying the light generated by the second light source module to an area narrower than the area on which light is applied by the first optical element.

In the summary described above of the invention, all the features necessary for the present invention are not enumerated and the side combinations of the groups of features may constitute the invention.

Figure 1 is a front view of a headlight 500 for a vehicle.

Figure 2 is a perspective view of the lighthouse 500 for the vehicle seen from an oblique portion and front thereof.

Figure 3 is an exploded perspective view of a light condenser unit 100.

FIG. 4 is an exploded perspective view of an intermediate diffusion unit 110.

Fig. 5 is an exploded perspective view of a wide diffusion unit 120.

Fig. 6 is a sectional view showing an example of an optical path of the light condenser unit 100.

Fig. 7 is a diagram showing an example of a light distribution pattern of the headlight 500 for the vehicle.

Fig. 8 is a diagram showing an example of a detailed structure of a light source module 10a.

Fig. 9 is a diagram showing an example of a detailed structure of a light source module 10b.

Fig. 10 is a diagram showing an example of a detailed structure of a light source module 10c.

Fig. 11 is a vertical sectional view showing the relationship of the arrangement of the semiconductor light emitting elements 12 of the light source modules 10b and 10c and the distance between the light emitting elements to semiconductor 12 and a reflector 80.

Fig. 12 is a diagram showing an example of a connection of the vehicle headlamp 500 in a first embodiment.

Fig. 13 is a diagram showing an example of the relationship between a light flux and a light emission efficiency with respect to the current density of the semiconductor light emitting element 12.

Fig. 14 is a diagram showing another example of the connection of the headlamp 500 for the vehicle in the first embodiment.

Fig. 15 is a diagram showing yet another example of the connection of the headlamp 500 for the vehicle in the first embodiment.

Fig. 16 is a front view showing an example of a structure of a headlight 500 for a vehicle according to a second embodiment of the present invention.

Fig. 17 is a diagram showing an example of a lighthouse connection 500 for the vehicle in the second embodiment.

Fig. 18 is a diagram showing an example of a lighthouse connection 500 for a vehicle in a third embodiment of the present invention.

The present invention will be described below by presenting various embodiments. The embodiments described below do not limit the invention. Furthermore, not all combinations of features described in the embodiments are essential to achieve the object of the present invention, i.e., to solve the problems raised.

Figures 1 and 2 show an example of a structure of a headlight 500 for a vehicle according to a first embodiment of the present invention. Figure 1 is a front view of the headlight 500 for the vehicle. Figure 2 is a perspective view of the headlight 500 for the vehicle seen from an oblique front portion of the headlight 50 for the vehicle of which a transparent cover 58, shown in Figure 1, is removed. In this embodiment, the forward and backward directions, the right and left directions, and the upward and downward directions respectively correspond to the forward and backward directions, to the right and left directions, and to the upward and downward directions. the bottom of the vehicle.

The headlight 500 for the vehicle is for example a vehicle headlight for applying crossover beams. Light condenser units 100, intermediate diffusion units 110 and a wide diffusion unit 120 are housed in a lamp chamber consisting of the transparent cover 58 and a support 54. In this embodiment, the headlight 500 for the vehicle comprises the three light condenser units 100, the two intermediate diffusion units 110 and a wide diffusion unit 120. The intermediate diffusion unit 110 has a round shape and emits light of a higher luminous intensity. that of the intermediate diffusion unit 110 and the wide diffusion unit 120. The intermediate diffusion unit 110 has a round shape and a smaller diameter than that of the light condenser unit 100. wide diffusion unit 120 has a long rectangular shape in a transverse direction. The intermediate diffusion unit 110 and the wide diffusion unit 120 emit lights of a lower light intensity than that of the light condenser unit 100, however, they have a light emission efficiency greater than that of the light condenser unit 100. The light condenser unit 100, the intermediate diffusion unit 110 and the wide diffusion unit 120 respectively have semiconductor light emitting elements described herein. below as light sources in order to illuminate the front part of the vehicle with the lights generated by the semiconductor light emitting elements. It is an object of this embodiment to provide a headlamp 500 for a vehicle in which a prescribed area in the vehicle distribution distribution pattern is illuminated with light having a high light intensity and the power consumed is low.

The light condenser units 100, the intermediate diffusion units 110 and the wide diffusion unit 120 are respectively fixed on the support 54 so as to be directed downward from about 0.5 to 0.6 ° relative to the front of the vehicle. The carrier 54 is fixed to the headlight 500 for the vehicle so as to be inclined by a control mechanism for adjusting the directions of the optical axes of the light condenser units 100, the intermediate diffusion units 110 and the control unit. wide diffusion 120. The light condenser units 100, the intermediate diffusion units 110 and the wide diffusion unit 120 respectively have light distribution patterns so as to respond to each type in order to form a distribution model. of light required for the lighthouse 500 for the vehicle as a whole. A plurality of thermal radiators 56 are provided on the rear surface of the support 54. The heat radiators 56 are made of a material having a higher thermal conductivity than that of a resin, such as metal, ceramic, etc. in order to radiate the heat generated respectively by the light condenser units 100, the intermediate diffusion units 110 and the wide diffusion unit 120.

Fig. 3 is an exploded perspective view of the light condenser unit 100. The light condenser unit 100 is formed to concentrically apply light to a relatively narrow area of the light distribution pattern. of the lighthouse 500 for the vehicle. The light condenser unit 100 comprises a lens 90a, a cover 92a, a reflector 80a, a light source portion 40a and a support 50a. The light source portion 40a has a light source module 10a and a base plate 14a having an upper surface on which the light source module 10a is mounted. The support 50a supports the light source 40a above and secures the lens 90a, the cover 92a and the reflector 80a with respect to the light source module 10a.

The reflector 80a is a substantially domed element attached to the upper portion of the light source module 10a and has a substantially elliptical spherical reflective surface therein having the optical axis of the light condenser unit 100 as central axis. More specifically, the reflective surface is formed in such a way that a section including the optical axis of the light condenser unit 100 forms substantially a quarter of the width of an elliptical shape having a separate point towards the back of the light source module 10a as a common top. With such a configuration, the reflector 80a condenses and reflects light emitted from the light source module 10a near the optical axis of the lens 90a to the front portion of the headlight 500 for the vehicle.

The cover 92a protects or reflects some of the light reflected by the reflector 80a to allow beams of light forming the light distribution pattern of the light condenser unit 100 to be incident on the lens 90a. The lens 90a allows a prescribed direction in the front portion of the headlight 500 for the vehicle to be illuminated with the lights reflected by the reflector 80a and the cover 92a. In this manner, the reflector 80a, the lens 90a and the cover 92a allow the prescribed area of the light distribution pattern with the lights generated by the light source module 10a. The light source module 10a shows an example of a second light source module of the present invention and the reflector 80a, the lens 90a and the cover 92a show an example of a second optical element of the present invention.

Fig. 4 is an exploded perspective view of the intermediate diffusion unit 110. The intermediate diffusion unit 110 comprises a lens 90b, a cover 92b, a reflector 80b, a light source portion 40b and a support 50b. The light source portion 40b has a light source module 10b and a base plate 14b having an upper surface on which the light source module 10b is mounted. In the intermediate scattering unit 110, the shapes of the reflector 80b and the cover 92b are set such that the lights are applied over an area wider than the area of the light condenser unit 100 in the distribution pattern headlight 500 for the vehicle. The relative positions of the reflector 80b, the lens 90b and the cover 92b are determined for the light source module 10b and are fixed on the support 50b. The light source module 10b shows an example of a first light source module of the present invention and the reflector 80b, the lens 90b and the cover 92b show an example of a first optical element.

Fig. 5 is an exploded perspective view of a wide diffusion unit 120. The wide diffusion unit 120 includes a reflector 80c, a light source portion 40c, and a support 50c. The light source module 40c has a base plate 14c on a surface of which a plurality of light source modules 10c are disposed on a line and mounted. The wide diffusion unit 120 is mounted such that a widest zone in the transverse direction of the light distribution pattern of the headlamp 500 for the vehicle is illuminated with the lights. The carrier 50c supports on the elongate light source portion 40c on which the plurality of light source modules 10c are mounted such that the light source portion 40c extends downward and in the transverse direction. Thus, the reflector 80c allows the front part of the headlamp 500 for the vehicle to be illuminated with the lights emitted downwards by the light source modules 10c.

The reflective inner surface of the reflector 80c is formed with a substantially parabolic shape in which a vertical section in the front and rear direction of the headlamp 500 is spread over the entire area of the inner surface and with a portion which comes into contact with the support 50c in the rear portion of the light source modules 10c as the top of a main axis. With such a configuration, the reflector 80c provides the widest zone in the transverse direction of the light distribution pattern of the headlamp 500 for the vehicle with the lights from the multiplicity of light source modules 10c arranged in the transverse direction, and vertically condensing the lumens to a prescribed area narrower than the zone in the transverse direction.

Fig. 6 is a sectional view showing an example of an optical path of the light condenser unit 100. The reflecting surface formed in the inner surface of the reflector 80a has its cross-sectional shape including the optical axis of the a light condenser unit 100 configured with a substantially elliptical shape and its eccentricity is set to be progressively increased from the vertical section to a horizontal section. In a vertical section including an optical axis, the lens 90a is arranged such that a focus position F2 in the back side corresponds to the focusing position of the reflective surface of the reflector 80a. The reflector 80a condenses the light of the light source module 10a to F2 on the reflective surface rearward of a reflection point A of a light 94 incident on the lower end of the lens 90a through F2. A light 95 which is reflected on the reflective surface in the rear portion of reflection point A of reflector 80a and passes near F2 is projected onto an upper limit of the light distribution pattern of light condenser unit 100 by the 90a lens. On the other hand, a light 96 which is reflected on a reflection point B of the reflector 80a is projected onto a lower limit of the light distribution pattern of the light condenser unit 100 by the lens 90a. A light 98 which is reflected between the reflection points A and B of the reflector 80a is projected between the upper limit and the lower limit of the light distribution pattern of the light condenser unit 100 through the lens 90a. The cover 92a integrally formed with the lens 90a is provided with a downward descending edge from F2. Thus, an optical image formed by the edge of the cover 92a and the reflector 80a on a focusing surface including F2 is inverted by the lens 90a and the inverted optical image is projected onto the front portion of the headlight 500 for the vehicle.

The focal point of the reflector 80a in the horizontal direction is provided in a portion closer to the side of the lens 90a than F2. In the edge of the cover 92a including F2, the two sides seen from an upper surface are curved forward in a manner corresponding to the curve of an image surface of the reflector 80a, i.e. curve of the focusing surface in the transverse direction. Therefore, the optical image formed on the forward edge of F2 as a function of reflection of the reflector 80a is enlarged in the transverse direction by the lens 90 and inverted and projected.

Figure 7 shows an example of the light distribution pattern of the headlight 500 for the vehicle. This light distribution pattern is a left passing beam light distribution pattern formed on a virtual vertical screen disposed at a position 25 m in front of the headlight 500 for the vehicle. The light distribution pattern is formed in the form of the synthesized light distribution pattern of a first light distribution pattern 600 and a second light distribution pattern 602 formed by the light condenser unit 100, a third light distribution pattern 604 formed by the intermediate diffusion unit 110 and a fourth light distribution pattern 606 formed by the wide diffusion unit 120. The light distribution pattern comprises, on its upper end, a horizontal section line CL1 and an oblique section line CL2 for determining a vertical cache limit.

The CL1 horizontal cut line is set slightly downward (downwards about 0.5 to 0.6 °) from the front surface (an intersection of a horizontal axis H and a vertical axis V) of the lighthouse 500 for the vehicle. The oblique cutting line CL2 is inclined to the left and upwards of approximately 15 ° with respect to the intersection of the vertical axis V and CL1. The horizontal section line CL1 of the first light distribution pattern 600 is formed by the horizontal edges of the covers 92a and 92b. The oblique cutting line CL2 is formed by the inclined edges of the covers 92a and 92b.

A part near the intersection of the horizontal axis H and the vertical axis V in the light distribution model is called a hot zone. The hot zone is preferably illuminated brighter than other areas of the light distribution model from a safety point of view. In this embodiment, the light condenser unit 100 uses the light of the light source module 10a which generates the higher brightness light than that of the intermediate diffusion unit 110 and the wide diffusion unit. 120 to illuminate the first light distribution pattern 600 as a narrower zone than the areas illuminated by lights by the intermediate diffusion unit 110 and the wide diffusion unit 120 with the light. having a high light intensity. Therefore, the lighthouse 500 for the vehicle can brightly illuminate the hot zone. Therefore, since the headlamp 500 for the vehicle can brighten more brightly an area to be noted while driving a vehicle, the safety while driving the vehicle at night can be improved.

Figures 8, 9 and 10 respectively show an example of the detailed structures of the light source modules 10a, 10b and 10c. Each of the light source modules 10a, 10b and 10c comprises a plurality of semiconductor light emitting elements 12, a fluorescent element 16 and a molding 18. The semiconductor light emitting element 12 is an LED having a light-emitting surface area of, for example, about 1 mm 2 and is provided on a base plate 14. The semiconductor light emitting element 12 generates, for example, a blue light, function of an electrical power received outside the light source modules 10a, 10b and 10c. The fluorescent element 16 is formed to cover the surfaces of the semiconductor light emitting elements 12 and to generate a yellow light as a complementary color to the blue light as a function of the blue lights generated by the semiconductor light emitting elements 12. In this case, the light source modules 10a, 10b and 10c generate white-colored lights according to the blue-colored lights and the yellow-colored lights generated respectively by the semiconductor light emitting elements 12 and the fluorescent elements 16. In other cases, the semiconductor light emitting elements 12 can generate ultraviolet rays with respect to the fluorescent element 16. In this case, the fluorescent element 16 can generate a white light as a function of the ultraviolet rays.

The molding 18 seals the semiconductor light emitting elements 12 and the fluorescent element 16. The molding 18 is formed for example with a semi-spherical shape with a material such as a resin allowing light to pass through which transmits the lights generated by the semiconductor light emitting elements 12 and the fluorescent element 16. The molding 18 may be formed with a material having a refractive index higher than that of the air so as to cover the Thus, the lights generated by the semiconductor light emitting elements 12 and the fluorescent element 16 can be emitted efficiently and used.

In this embodiment, the light source module 10a comprises two semiconductor light emitting elements 12 having substantially equal light emitting surfaces. The two semiconductor light emitting elements 12 provided in the light source module 10a are connected in series with each other. Here, a connection means not only a physical connection but also an electrical connection. The light source modules 10a and 10b respectively comprise four semiconductor light emitting elements 12 having light emitting surfaces substantially equal to the light emitting surfaces of the half light emitting elements. conductor 12 provided in the light source module 10a. When the multiplicity of the semiconductor light emitting elements 12 provided in the light source modules 10b and 10c is mounted on the vehicle, the semiconductor light emitting elements are arranged to be arranged. horizontally in the transverse direction of the vehicle. In the four semiconductor light emitting elements 12 provided respectively in the light source modules 10b and 10c, the sets of the semiconductor light emitting elements which are respectively connected in series are connected in parallel. .

In this case, when the semiconductor light emitting elements 12 have substantially equal light emission surfaces, when electric current supplied to the semiconductor light emitting elements 12 increases, semiconductor light emission generate larger light flux lights. In addition, when the light emitting surfaces are equal, if the generated light flux increases, the light intensity as the light flux per unit solid angle is increased. At this time, the brightness as light intensity per unit area is also increased. Therefore, when the electric current substantially equal to that of the light source modules 10b and 10c is delivered to the light source module 10a, the light source module 10a generates the brightness of the higher brightness than that of the light source modules 10a and 10c. light source 10b and 10c. Thus, the light source modules 10a, 10b and 10c can be treated as the light source module 10 whose nominal direct current is substantially equal. Here, the nominal direct current indicates electric current supplied to the light source modules 10a, 10b and 10c in order to illuminate the light source modules 10a, 10b and 10c respectively with desired light quantities.

As described above, the headlight 500 for the vehicle may utilize a current source for delivering the electric current having a single current value to illuminate the light source modules 10a, 10b and 10c that generate the lights of a different brilliance. Therefore, parts such as base plugs or cables having substantially the same current capacity can be used. Therefore, the lighthouse 500 for the vehicle can be built at low cost. Further, since the light source modules 10a, 10b and 10c that generate the different brightness light can be constructed using substantially the same semiconductor light emitting elements 12, the light source modules 10 can be built at low cost.

Fig. 11 is a vertical sectional view showing the relationship of the arrangement of the semiconductor light emitting elements 12 of the light source modules 10b and 10c and the distance between the light emitting elements to semiconductor and a reflector 80. A transverse direction in this figure shows the front and rear direction of the vehicle. The reflector 80 forms from the lights generated by the semiconductor light emitting elements 12 a light distribution pattern having the length L3 in the vertical direction and elongated in the transverse direction of the vehicle on a virtual vertical screen arranged in a position 25 tn in front of the lighthouse 500 for the vehicle. Here, when the semiconductor light emitting elements 12 of the light source modules 10b and 10c are arranged in such a manner that the semiconductor light emitting elements are arranged horizontally in the forward direction and rear of the vehicle, for example as shown by A, the distance between the semiconductor light emitting elements 12 and the reflector 80 is L1. However, in this embodiment, when the multiplicity of the semiconductor light emitting elements 12 of the light source modules 10b and 10c is mounted on the vehicle, the semiconductor light emitting elements are arranged horizontally in the transverse direction of the vehicle, as shown by B. Thus, the distance between the semiconductor light emitting elements 12 and the reflector 80 is L2 shorter than L1. As a result, the size of the intermediate diffusion units 110 and the wide diffusion unit 120 can be made small.

Figure 12 shows an example of a headlight connection 500 for the vehicle in the first embodiment. The lighthouse 500 for the vehicle comprises a lighting circuit 700 as well as the light condenser units 100, the intermediate diffusion units 110 and the wide diffusion unit 120. The light condenser units 100, the diffusion units intermediate 110 and wide diffusion unit 120 are connected in series. The lighting circuit 700 delivers an electric current substantially equal to the light condenser units 100, the intermediate diffusion units 110 and the wide diffusion unit 120 which are connected in series. In such a connection, the lighting unit 700 delivers the electric current to the light condenser units 100 so that the current density of the electric current supplied to the semiconductor light emitting elements 12 The light condenser 100 is higher than the current density of the electric current delivered respectively to the semiconductor light emitting elements 12 of the intermediate diffusion units 110 and to the wide diffusion unit 120.

Here, when the lighting circuit 700 delivers the electric current of, for example, 700 mA to the light condenser units 100, the intermediate diffusion units 110 and the wide diffusion unit 120 which are connected in series, the electrical current of 700 mA is respectively supplied to the semiconductor light emitting elements 12 of the light condenser units 100. The electric current of 350 mA is delivered respectively to the semi-light emitting elements -conductor 12 of the intermediate diffusion units 110 and the wide diffusion unit 120. Thus, the semiconductor light emitting elements 12 of the light condenser units 100 respectively generate the lights having the highest brightness than that of the semiconductor light emitting elements 12 of the intermediate diffusion units 110 and the wide diffusion unit 120. In this way, the The light source modules 10 that generate the different brightness lights can be illuminated using single wiring, so that the number of headlight wirings 500 for the vehicle can be reduced. The headlight 500 for the vehicle can therefore be miniaturized.

In addition, when any of the light source modules 10a, 10b and 10c are disconnected, the headlight 500 for the vehicle does not light. Thus, the headlight 500 for the vehicle can inform a driver that any of the light source modules 10a, 10b and 10c of the headlamp 500 for the vehicle is disconnected.

An illumination circuit 700 shows an example of a first power source and a second power source of the present invention.

Fig. 13 shows an example of the relationship of a light flux and a light emission efficiency with respect to the current density of the semiconductor light emitting element 12. When the density As the current of the semiconductor light emitting element 12 is increased, the light flux generated by the semiconductor light emitting element 12 is increased. On the other hand, the light emission efficiency is lowered. Assuming that the light emitting surface of the semiconductor light emitting element 12 in this embodiment is, for example, 1 mm 2, when the electric current of 700 mA is delivered, the output of light emission of the semiconductor light emitting element 12 has a value represented by a point D. On the other hand, when the electric current of 350 mA is delivered, the light emission efficiency of the semiconductor light emitting element 12 has a mean value represented by a point A and is greater than that when the electric current of 700 mA is output. In addition, when the electric current of 350 mA is delivered, the light flux of the light generated by the semiconductor light emitting element 12 has a value represented by a point B. On the other hand, when the electrical current of 700 mA is delivered, the light flux of the light generated by the semiconductor light emitting element 12 has a value represented at a point C and is greater than that when the electric current of 350 mA is delivered. Here, when the semiconductor light emitting elements 12 have substantially the same light emitting surfaces, if the generated light fluxes are different, the light intensity as the light flux per unit of light solid angle is different and the brightness (or luminance) as light intensity per unit area is also different at the same time. Therefore, in the semiconductor light emitting elements 12 having substantially the same light emitting surfaces, the semiconductor light emitting element 12 to which a large amount of electrical power is delivered emits the light whose brightness is higher than that of the semiconductor light emitting element 12 to which a small amount of electric current is delivered.

In this embodiment, the light source modules 10a, 10 and 10c comprise the semiconductor light emitting elements 12 having substantially the same light emitting surfaces. Since a greater amount of electric current is supplied to the semiconductor light emitting elements 12 of the light source module 10a than that delivered to the semiconductor light emitting elements 12 of the light source modules 10b and 10c, the light source module 10a generates the lights having a higher brightness than that of the light source modules 10b and 10c. In addition, the light condenser units 100 concentrically apply the lights generated by the light source modules 10a to a relatively narrow area of the light distribution pattern. The intermediate diffusion units 110 and the wide diffusion units 120 diffuse and apply the lights generated by the light source modules 10b and 10c to the relatively wide areas of the light distribution pattern. As a result, the light condenser units 100 apply lights having a relatively higher light intensity than the lights applied by the intermediate diffusion units 110 and the wide diffusion unit 120.

The light source modules 10a, 10b and 10c have the semiconductor light emitting elements 12 having substantially equal light emission surfaces. Since a smaller amount of electric current is supplied to the semiconductor light emitting elements 12 of the light source modules 10b and 10c than that supplied to the semiconductor light emitting elements 12 of the light source module 10a light source, the light emission efficiency of the light source modules 10b and 10c is higher than that of the light source module 10a. Thus, the light emission efficiency of the intermediate diffusion units 110 and the wide diffusion unit 120 can be increased more than that of the light condenser units 100. Therefore, the hot zone can be illuminated with the lights. having a high light intensity and a headlight 500 for low power consumption vehicle can be realized.

Figure 14 shows another example of a headlight connection 500 for the vehicle in the first embodiment. The headlight 500 for the vehicle comprises a light source line 502 in which a light condenser unit 100, two intermediate scattering units 110 and a light source module 10c of the wide diffusion unit 120 are connected in series. and a light source line 504 in which two light condenser units 100 and two light source modules 10c in the wide diffusion unit 120 are connected in series. The lighting circuit 700 delivers independently of the electrical energy respectively to the light source line 502 and the light source line 504. Thus, even when any of the light source modules 10 included in a light source line of the light source line 502 and the light source line 504 is disconnected, the front part of the vehicle can be illuminated with the other light source. Therefore, a security of a vehicle traveling at night can be maintained. In addition, the output voltage of the lighting circuit 700 can be lowered further than that when the headlight 500 for the vehicle is made by a single wiring. Therefore, the lighting circuit 700 can be constructed at low cost, and a user can be prevented from receiving an electric shock.

Further, the light source line 502 and the light source line 504 preferably comprise a multiplicity of types of light source units so as to illuminate the substantially complete portion of the light distribution pattern. Thus, even when any of the light source modules 10 included in a light source line of the light source line 502 and the light source line 504 are disconnected, the substantially complete portion of the light source module 50 is disconnected. Vehicle light distribution can be illuminated with the other light source line. In addition, the nominal forward voltage of the light source modules 10 is preferably substantially equal. Here, the nominal direct voltage refers to the voltage generated respectively in the light source module 10a, 10b and 10c when the light source modules 10a, 10b and 10c are respectively lit with desired amounts of light. Thus, for example, only when the number of the plurality of light source modules 10 connected to the light source line 502 or 504 is the same, the light source modules 10 included in the light source line 502 can be replaced by the light source modules 10 included in the light source line 504. Therefore, once the positions of the light source modules 10 in the headlight 500 for the vehicle are set from the point of view of a design or an optical design, the wiring of each of the light source modules 10 can be easily achieved.

In this embodiment, the light source modules 10a, 10b and 10c respectively have the different number of semiconductor light emitting elements 12 which respectively have substantially light emitting surfaces. equal. The multiplicity of semiconductor light emitting elements 12 provided in the light source module is connected in series. The multiplicity of semiconductor light emitting elements 12 provided in the light source module 10b or 10c is connected in parallel. Compared to this, as another example, the light source modules 10a, 10b and 10c may respectively have a semiconductor light emitting element 12 and the light emitting surface of the light emitting element. semiconductor light emission 12 of the light source module 10a may be smaller than the light emitting surfaces of the semiconductor light emitting elements 12 of the light source modules 10b and 10c. Even in such a structure, when a lighting circuit 700 delivers an electric current substantially equal to the light source modules 10a, 10b and 10c, the light source module 10a can emit the higher brightness light than the light source modules 10b and 10c.

In addition, as another example, the light source modules 10a, 10b and 10c may respectively have a semiconductor light emitting element 12 having a substantially equal light emission surface. A lighting circuit 700 may deliver a greater amount of electric current to the light source module 10a than that of an electric current supplied to the light source modules 10b and 10c. In this case, the light source module 10a may also generate the higher brightness light than the light source modules 10b and 10c.

As yet another example, the light source modules 10a, 10b and 10c may respectively have a multiplicity of semiconductor light emitting elements 12 which respectively have substantially equal light emission surfaces. . The number of the plurality of semiconductor light emitting elements 12 provided in the light source module 10a may be greater than that of the multiplicity of semiconductor light emitting elements 12 provided. respectively in the light source modules 10b and 10c and they can be connected in series. The multiplicity of semiconductor light emitting elements 12 respectively provided in the light source modules 10b and 10c can be connected in parallel. Even in this structure, when a lighting circuit 700 delivers an electric current substantially equal to the light source modules 10a, 10b and 10c, the light source module 10a can also emit the light of brightness greater than that of the modules light source 10b and 10c.

Fig. 15 shows yet another connection of the headlamp 500 for the vehicle in the first embodiment. The headlight 500 for the vehicle further includes a resistor 140. In this embodiment, four semiconductor light emitting elements 12 respectively provided in the light source modules 10b and 10c are connected in series. Three light source modules 10c of the wide diffusion unit 120 are connected in series. The two intermediate diffusion units 110 and the resistor 140 are connected in series. The intermediate diffusion units 110 and the resistor 140 which are connected in series are connected in parallel to a wide diffusion unit 120. Three light condenser units 100 are connected in series. The light condenser units 100 are connected in series with the wide diffusion unit 120. Here, the resistance value of the resistor 140 is set such that a value of an electric current delivered to the intermediate diffusion units 110 is substantially equal to that of an electric current delivered to the wide diffusion unit 120. In this embodiment, since the multiplicity of light source modules 10 for generating the lights of different brightness can be illuminated by the low number of wiring, the lighthouse 500 for the vehicle can be miniaturized.

Fig. 16 is a front view showing an example of a structure for a headlamp 500 for a vehicle according to a second embodiment of the present invention. In FIG. 16, structures designated by the same references as those of FIG. 1 have the same structures as those shown in FIG. 1 or similar functions with the exception of the points described below. Therefore, an explanation of these is omitted. In this embodiment, the headlight 500 for the vehicle comprises three light condenser units 100, four intermediate diffusion units 110 and six wide diffusion units 130. The wide diffusion unit 130 is round and has a smaller diameter. that the diameter of the intermediate diffusion unit 110. The wide diffusion unit 130 emits light having a lower light intensity than that of the light condenser unit 100, however, has a transmission efficiency of higher light than that of the light condenser unit 100. The six wide diffusion units 130 are constructed to form the fourth light distribution pattern 606 (see Fig. 7) which is the widest zone in the transverse direction in the light distribution pattern.

Fig. 17 shows an example of a headlight connection 500 for the vehicle in the second embodiment. In FIG. 17, structures designated by the same references as those of FIG. 12 have the same structures as those represented in FIG. 12 or functions similar to those represented in FIG. 12 with the exception of the points described below. . Therefore an explanation of these is omitted. A light source line 506 includes four intermediate diffusion units 110 and a wide diffusion unit 130 which are connected in series. A light source line 508 comprises five wide diffusion units 130 which are connected in series. A light source line 510 includes the light source line 506 and the light source line 508 which are connected in parallel with each other. Three light condenser units 100 which are connected together in series are connected in series with the light source line 510. The wide diffusion units 130 comprise light source modules 10d. A light source module 10a, a light source module 10b and the light source module 10d respectively have two semiconductor light emitting elements 12 which are connected in series. In this embodiment, when a nominal direct electric current is delivered respectively to the intermediate diffusion units 110 and the wide diffusion units 130, a voltage drop is substantially equal. Therefore, when the nominal direct electrical current is delivered respectively to the light source line 506 and the light source line 508, the voltage drop is substantially equal. Thus, an electric current delivered to the semiconductor light emitting elements 12 provided in the light condenser units 100 is twice as large as an electric current supplied to the semiconductor light emitting elements 12 respectively provided in the intermediate diffusion units 110 and the wide diffusion units 130. Therefore, the light source module 10a generates the higher brightness light than the light source modules 10b and 10d. Therefore, in this embodiment, since the multiplicity of light source modules 10 for emitting lights of different brightness can be illuminated in the same way by the low number of wiring, the headlight 500 for the vehicle can be miniaturized .

Fig. 18 shows an example of a connection of a headlamp 500 for a vehicle in a third embodiment of the present invention. In FIG. 18, structures designated by the same references as those of FIG. 12 have the same structures as those represented in FIG. 12 or functions similar to those represented in FIG. 12 with the exception of the points described below. . Therefore, an explanation of these is omitted. The lighthouse 500 for the vehicle comprises three light condenser units 100, two intermediate diffusion units 110 and three wide diffusion units 130. In each of the light condenser units 100, intermediate diffusion units 110 and diffusion units 130, one end is connected to a reference potential terminal of a lighting circuit 700 and the other end is connected to a positive potential terminal of the lighting circuit 700 via a resistor 142. The wide broadcast units 130 have light source modules 10d. The resistance values of the resistors 142 are respectively set so that when a nominal voltage for turning on the light source modules 10 with desired amounts of light is applied to the light source modules by the light circuit. In illumination 700, the light source modules 10 are respectively held at a nominal forward voltage by a voltage drop generated in the resistors 142 as a function of a nominal direct electrical current delivered respectively to the light source modules. 10. The light source module 10a has two semiconductor light emitting elements 12 which are connected in series with each other. The light source modules 10b and 10d respectively have four semiconductor light emitting elements. Two semiconductor light emitting elements which are connected in series are connected parallel to two other semiconductor light emitting elements which are connected in series. The light emitting surfaces of the semiconductor light emitting elements 12 respectively provided in the light source modules 10a, 10b and 10d are substantially equal. Further, in this embodiment, the nominal direct voltage generated when the nominal direct electrical current is delivered respectively to the light source modules 10a, 10b and 10d is substantially equal.

Here, when the nominal voltage is applied respectively to the light source modules 10a, 10b and 10d through the resistors 142, an amount of electric current supplied to the semiconductor light emitting elements 12 provided in the Light source module 10a is larger than that of an electric current supplied to semiconductor light emitting elements 12 provided in light source modules 10b and 10d. Since the light emitting surfaces of the semiconductor light emitting elements of the light source modules 10 are substantially equal, the light source modules 10a generate the higher brightness lights than the lights generated by the light source modules 10a. the light source modules 10b and 10d. Thus, the lighting circuit 700 for generating a single voltage is used so that the multiplicity of the light source modules 10 for generating the lights of different brightness can be turned on. As a result, the wiring of the headlight 500 for the vehicle can be reduced. Further, since the nominal forward voltage is substantially equal when the normal electric current is delivered respectively to the light source modules 10, the voltage drop generated respectively in the resistors 142 can be decreased.

Therefore, the output voltage of the illumination circuit 700 can be lowered near the nominal forward voltage of the light source modules 10. Therefore, the illumination circuit 700 can be formed at low cost and a user can be prevented from receiving an electric shock.

In this embodiment, the headlight 500 for the vehicle is provided with the plurality of light source units for applying lights having two types of light intensity. However, as another example, a plurality of light source units for applying lights having three or more types of light intensity can be provided. Thus, a light distribution pattern can be formed with higher precision.

As is evident from the above description, according to this embodiment, the headlamp 500 for the vehicle, wherein the hot zone in the light distribution pattern of the vehicle headlight can be illuminated with the light having the high light intensity and power consumption is low, can be expected.

The present invention is described above with reference to the embodiments. However, the technical scope of the present invention is not limited to the scope defined by the embodiments described above. It is obvious to a person skilled in the art that various changes or improvements may be applied to the embodiments described above. Forms including these changes or improvements may be included within the technical scope of the present invention.

Claims (5)

A vehicle headlight (500) comprising: a first light source module (10b; 10c) having at least one semiconductor light emitting element (12); a first optical element (80b, 90b, 92b, 80c) for applying light generated by the first light source module (10b) to an area of a light distribution pattern of the vehicle headlight; a second light source module (10a) having at least one semiconductor light emitting element (12) and generating light having a higher brightness than that of the light of the first light source module ( 10b); and a second optical element (80a, 90a, 92a) for applying the light generated by the second light source pattern (10a) to an area narrower than the area on which light is applied by the first optical element (80b). , 90b, 92b), characterized in that said vehicle headlight (500) further comprises: a first electric power source (700) for supplying an electric current to the first light source module (10b); and a second electric power source (700) for supplying to the second light source module (10a) an electric current such as the current density of the electric current supplied to the semiconductor light emitting element ( 12) provided in the second light source module (10a) is greater than the current density of the electric current supplied to the semiconductor light emitting element (12) provided in the first source module of light (10b; 10c). The vehicle headlamp (500) according to claim 1, characterized in that the semiconductor light emitting element (12) of the second light source module (10a) has a light emitting surface smaller than that of the semiconductor light emitting element (12) of the first light source module (10b; 10c) and the second electric power source (700) delivering to the second light source module (10a) an electric current substantially equal to the electric current supplied to the first light source module (10b) by the first electric power source (700). The vehicle headlight (500) according to claim 1, characterized in that the semiconductor light emitting element (12) of the second light source module (10a) has a light emitting surface substantially equal to that of the semiconductor light emitting element (12) of the first light source module (10b; 10c) and the second power source (700) providing to the second light source module (10a) an electric current greater than the electric current supplied to the first light source module (10b) by the first electric power source (700). The vehicle headlamp (500) according to claim 1, characterized in that the first light source module (10b; 10c) comprises a multiplicity of semiconductor light emitting elements (12) connected in parallel and having substantially equal light emitting surfaces, the second light source module (10a) comprises a plurality of series-connected semiconductor light emitting elements (12) having the emitting surfaces substantially equal to those of the plurality of semiconductor light emitting elements (12) included in the first light source module (10b) and the second electric power source (700) to the second module light source (10a) an electric current substantially equal to the electric current delivered to the first light source module (10b) by the first electric power source (700). An automobile headlight (500) for applying a passing beam used for an automobile, comprising: a first light source module (10b; 10c) having at least one semiconductor light emitting element ( 12); a first optical element (80b, 90b, 92b; 80c) for applying light generated by the first light source module (10b; 10c) to an area of a light distribution pattern of the vehicle headlight; a second light source module (10a) having at least one semiconductor light emitting element (12) and generating light having a brightness greater than that of the light of the first light source module (10b) 10c); and a second optical element (80a, 90a, 92a; 80c) for applying the light generated by the second light source module (10a) to an area narrower than the area on which the light is applied by the first optical element (80b, 90b, 92b, 80c), characterized in that said automobile headlight (500) further comprises: a first electric power source (700) for supplying an electric current to the first light source module (10b) ); and a second electric power source (700) for supplying to the second light source module (10a) an electric current such as the current density of the electric current supplied to the semiconductor light emitting element ( 12) provided in the second light source module (10a) is higher than the current density of the electric current supplied to the semiconductor light emitting element (12) provided in the first source module of light (10b; 10c).